Pembrolizumab versus Ipilimumab in Advanced Melanoma

We sought to compare the tumor profiles of brain metastases from common cancers with those of primary tumors and extracranial metastases in order to identify potential targets and prioritize rational treatment strategies. Tumor samples were collected from both the primary and metastatic sites of nonsmall cell lung cancer, breast cancer and melanoma from patients in locations worldwide, and these were submitted to Caris Life Sciences for tumor multiplatform analysis, including gene sequencing (Sanger and next‐generation sequencing with a targeted 47‐gene panel), protein expression (assayed by immunohistochemistry) and gene amplification (assayed by in situ hybridization). The data analysis considered differential protein expression, gene amplification and mutations among brain metastases, extracranial metastases and primary tumors. The analyzed population included: 16,999 unmatched primary tumor and/or metastasis samples: 8,178 nonsmall cell lung cancers (5,098 primaries; 2,787 systemic metastases; 293 brain metastases), 7,064 breast cancers (3,496 primaries; 3,469 systemic metastases; 99 brain metastases) and 1,757 melanomas (660 primaries; 996 systemic metastases; 101 brain metastases). TOP2A expression was increased in brain metastases from all 3 cancers, and brain metastases overexpressed multiple proteins clustering around functions critical to DNA synthesis and repair and implicated in chemotherapy resistance, including RRM1, TS, ERCC1 and TOPO1. cMET was overexpressed in melanoma brain metastases relative to primary skin specimens. Brain metastasis patients may particularly benefit from therapeutic targeting of enzymes associated with DNA synthesis, replication and/or repair.

Section: Discussionmentioning

confidence: 99%

Profiles of brain metastases: Prioritization of therapeutic targets

Ferguson

Zheng

Xiu

et al. 2018

“…Immunotherapy using antibodies targeting checkpoint proteins has become of increasing interest and a number of clinical trials using these antibodies for several different cancer types have shown clinical responses 22, 23, 24, 25, 26, 27, 28. However, studies with animal models and cancer patients have also shown that combining antibody blockade of the PD‐1/PD‐L1 axis with other forms of immunotherapy can lead to more meaningful clinical responses 32, 33, 34, 35.…”

Section: Discussionmentioning

confidence: 99%

“…One consistency is demonstrations that blocking PD‐1 increased progression‐free survival of patients with melanoma, although the rates of complete responses were low 23. Similarly, blocking PD‐1 in patients with non‐small‐cell lung cancer prolonged progression‐free survival, but cancer nevertheless progressed in almost all patients 25.…”

Section: Discussionmentioning

confidence: 99%

Transient immunological and clinical effectiveness of treating mice bearing premalignant oral lesions with PD‐1 antibodies

Levingston

Young

2017

A carcinogen‐induced premalignant oral lesion model that progresses to oral cancer was used to examine the impact of blocking PD‐1 on cytokine expression and on progression of lesions to cancer. The results of this study show increased production of IL‐2 and the inflammatory cytokines IL‐6, IL‐17 and TNF‐α by spleen cells of lesion‐bearing mice that were treated with PD‐1 antibody for 1 week compared to cytokine production by spleen cells of lesion‐bearing mice treated with control antibody. Production of IFN‐γ increased at 3 weeks of PD‐1 antibody treatment, although production of the other Th1 and inflammatory mediators declined. By 5 weeks, levels of these cytokines declined for both control and PD‐1 antibody‐treated mice. Flow cytometric analysis for IFN‐γ‐expressing cells showed shifts in CD4+ cells expressing IFN‐γ consistent with the changes in cytokine secretion. Whether or not treatment generated reactivity to lesions or HNSCC was determined. Spleen cells from PD‐1 antibody‐treated mice were stimulated by lysates of premalignant lesion and HNSCC tongue tissues to produce increased levels of Th1 and select inflammatory cytokines early in the course of PD‐1 antibody treatment. However, with continued treatment, reactivity to lesion and HNSCC lysates declined. Analysis of clinical response to treatment suggested an early delay in lesion progression but, with continued treatment, lesions in PD‐1 antibody‐treated mice progressed to the same degree as in control antibody‐treated mice. Overall, these results show an early beneficial response to PD‐1 antibody treatment, which then fails with continued treatment and lesion progression.

“…The role of immune system in clearing cancer cells has recently been appreciated after the major success in the blockade of the T‐cell inhibitory molecule, PD‐L1, which is expressed by cancer cells to evade immune response 5. However, beside its established role in the immune response, PD‐L1 expression has intrinsic effect on cancer cells themselves (reviewed by Ritprajak et al 6…”

Section: Introductionmentioning

confidence: 99%

PD‐L1 promotes OCT4 and Nanog expression in breast cancer stem cells by sustaining PI3K/AKT pathway activation

Almozyan

Çolak

Mansour

et al. 2017

193

120

The expression of PD‐L1 in breast cancer is associated with estrogen receptor negativity, chemoresistance and epithelial‐to‐mesenchymal transition (EMT), all of which are common features of a highly tumorigenic subpopulation of cancer cells termed cancer stem cells (CSCs). Hitherto, the expression and intrinsic role of PD‐L1 in the dynamics of breast CSCs has not been investigated. To address this issue, we used transcriptomic datasets, proteomics and several in vitro and in vivo assays. Expression profiling of a large breast cancer dataset (530 patients) showed statistically significant correlation (p < 0.0001, r = 0.36) between PD‐L1 expression and stemness score of breast cancer. Specific knockdown of PD‐L1 using ShRNA revealed its critical role in the expression of the embryonic stem cell transcriptional factors: OCT‐4A, Nanog and the stemness factor, BMI1. Conversely, these factors could be induced upon PD‐L1 ectopic expression in cells that are normally PD‐L1 negative. Global proteomic analysis hinted for the central role of AKT in the biology of PD‐L1 expressing cells. Indeed, PD‐L1 positive effect on OCT‐4A and Nanog was dependent on AKT activation. Most importantly, downregulation of PD‐L1 compromised the self‐renewal capability of breast CSCs in vitro and in vivo as shown by tumorsphere formation assay and extreme limiting dilution assay, respectively. This study demonstrates a novel role for PD‐L1 in sustaining stemness of breast cancer cells and identifies the subpopulation and its associated molecular pathways that would be targeted upon anti‐PD‐L1 therapy.